EFFECT OF FINES ON PROPERTIES OF CONCRETE /IN SWEDISH/

IT HAS BEEN FOUND FROM THE TESTS WHICH ARE DESCRIBED THAT THE WORKABILITY OF FRESH CONCRETE AND THE STRENGTH OF HARDENED CONCRETE REACHED OPTIMUM VALUES WHEN THE AMOUNT OF AVERAGE FINNISH NATURAL FINES, OR THAT OF NEARLY ALL CRUSHED-ROCK FINES, WHICH CONSISTED OF QUARTZITE, LIMESTONE, AND FELDSPAR, WAS INCREASED. IN GENERAL THE OPTIMUM WORKABILITY WAS OBSERVED AT THE SAME PERCENTAGE OF FINES AS THAT WHICH WAS REQUIRED FOR THE OPTIMUM STRENGTH. THE PERCENTAGE OF FINES WHICH CORRESPONDS TO THE OPTIMUM CAN BE ESTIMATED REGARDLESS OF THE QUALITY OF THE FINES, BY USING THE SAME VALUES OF THE RATIO OF THE WATER VOLUME TO THE SUM OF THE CEMENT AND FINES VOLUMES CONTAINED IN THE CONCRETE. THE AIR CONTENT OF THE FRESH CONCRETE WAS INCREASED BY NATURAL FINES, WHEREAS IT WAS REDUCED BY CRUSHED-ROCK FINES PARTICULARLY WHEN THEY WERE VERY FINEGRAINED. AS A RESULT OF THESE TWO OPPOSITE EFFECTS, THE FROST RESISTANCE OF THE CONCRETE MADE WITH NATURAL FINES WAS INCREASED, WHILE IT WAS GREATLY DIMINISHED BY THE USE OF CRUSHED-ROCK FINES. OWING TO THEIR SMALL SPECIFIC SURFACE AREA, THE AVERAGE FINNISH NATURAL FINES DID NOT REDUCE THE AMOUNT OF BLEEDING (WATER GAIN) OF THE CONCRETE. THE INCREASE IN THE STRENGTH OF THE CONCRETE ATTRIBUTABLE TO THE USE OF NATURAL FINES WAS RELATIVELY SLIGHT, BUT THE CORRESPONDING INCREASE BECAME MUCH MORE NOTICEABLE WHEN USE WAS MADE OF CRUSHED-ROCK FINES. THE CHANGES IN THE STRENGTH OF THE CONCRETE ATTRIBUTABLE TO THE USE OF FINES ARE DEPENDENT ON A COMBINED EFFECT OF MANY FACTORS, SUCH AS CHANGES IN THE WORKABILITY IN THE AIR CONTENT AND IN THE AMOUNT OF BLEEDING OF FRESH CONCRETE AS WELL AS IN A POSSIBLE PHYSICAL AND CHEMICAL BOND BETWEEN THE CEMENT PASTE AND THE PARTICLES OF FINES. /RRL/A/

• Supplemental Notes:
  • Vol 11, No 3, PP 225-252, 20 FIG, 4 TAB, 3 PHOT, 28 REF
• Authors:
  • Poijarvi, H
• Publication Date: 1967

Media Info

• Serial:
  • Nordisk Betong /Sweden/

Subject/Index Terms

• TRT Terms: Air content; Bleeding; Cement; Chemical bond; Concrete hardening; Crushed rock; Fines (Materials); Frost protection; Natural resources; Pastes; Polymer concrete; Surfaces; Workability
• Uncontrolled Terms: Hardened concrete; Surface area
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00212965
• Record Type: Publication
• Source Agency: Road Research Laboratory /UK
• Files: TRIS
• Created Date: Jun 1 1970 12:00AM